table: Enable engine without MPI by cleaning up sub-adios APIs
Created by: bradking
Manage table's sub-adios through the core API. Avoid using the public C++11 bindings API from the core implementation.
With this we can now access the core ADIOS constructor that accepts the Comm abstraction instead of a raw MPI_Comm. We can use Comm::World()
instead of MPI_COMM_WORLD
. This allows us to enable the Table engine even when ADIOS is built without MPI.